What Low-VOC Carpet Actually Means: How to Read a Green Label Plus Certificate

Pei Xiaochuan✓

Chairman, UNIJOY · 15 years in carpet tile·19 July 2026·9 min read

Technically reviewed by Pei Xiaochuan, Chairman

TL;DR

Green Label Plus is the carpet industry's low-emission certification, run by The Carpet and Rug Institute and tested to California Department of Public Health Section 01350. A certificate is not a slogan — it is a document with fields you can check. The four that matter are the label ID (look it up in CRI's certified-product database), the product category code (it tells you which construction was tested, not the whole catalogue), the TVOC figure, and the expiry date. UNIJOY's certificate GLP100230 covers category CN13, nylon with PVC backing in modular tile format, at TVOC of 0.5 mg/m³ or below under both private-office and school-classroom scenarios, valid until 31 December 2026. If a supplier says "low VOC" without giving you a number, a category and a date, they have told you nothing you can check.

Open-plan office with planting, timber slat screen and grey-blue carpet tile — the enclosed interior where flooring emissions matter

1. What the label certifies — and what it does not

“Low VOC” on a product page is a claim. A Green Label Plus certificate is a document. The difference matters, because one can be checked and the other cannot.

Green Label Plus is run by The Carpet and Rug Institute (CRI), the US carpet industry body, and tests finished product for chemical emissions into indoor air under California Department of Public Health Section 01350. Certified products are issued a label ID and listed in a public database.

What it certifies is narrower than most buyers assume, and the narrowness is the useful part:

	Green Label Plus covers	It does not cover
Scope	Chemical emissions into indoor air from the finished product	Recycled content, carbon footprint, durability or fire performance
Subject	The specific construction submitted for testing	Every product in the supplier’s catalogue by default
Basis	Chamber testing by an independent laboratory	Manufacturer self-declaration
Duration	A fixed term, with re-testing to stay listed	Permanent status once granted

If you need the environmental footprint rather than the air-quality position, that is a different document — an Environmental Product Declaration. The two are often confused. Ours is EPD-IES-0026525:001, and it answers a different question entirely.

Enclosed lounge area with timber slat walls, low seating and light patterned carpet tile — Emissions matter in proportion to how enclosed a space is and how much surface area the material covers. Flooring is usually the largest single surface in a room, which is why it is one of the first materials a green building assessor asks about.

2. What sits behind the number

A certificate hands you a short summary. It is worth knowing what produced it, because the protocol is stricter than the single TVOC figure suggests.

Named compounds, not just a total. The programme screens the 31 compounds listed in California 01350, plus six specific to carpet — including 4-phenylcyclohexene, the compound responsible for the classic “new carpet smell”, and caprolactam.
The limit is half the health threshold. Emissions must come in at no more than half the chronic reference exposure level for each compound. Formaldehyde is the exception and is held to the full level.
Testing is not one-and-done. Initial certification runs a 14-day chamber test. Listed products then face a 24-hour annual check and a full 14-day re-test every two years. A product that stops complying stops being listed.

That third point is the one to hold on to. A Green Label Plus listing is a live status, not a trophy from a test done years ago — which is exactly why the expiry date in section 5 deserves more attention than it usually gets.

3. Reading a certificate, field by field

Here is our own certificate as a worked example. The point is not the specific values — it is that you should expect all four of these fields from any supplier, and be able to check each one.

Field	On our certificate	What to do with it
Label ID	GLP100230	Look it up in CRI’s certified-product database. This is the only field that proves the document is real.
Product category	CN13 — nylon with PVC backing, modular tile	Check it describes what you are buying. A certificate covers the construction tested, not the whole range.
Test basis	California DPH Section 01350 v1.2; method ASTM D-5116	Confirms it is chamber testing to a named standard, not an in-house claim.
Result	TVOC ≤ 0.5 mg/m³, private office and school classroom	Two scenarios, not one. Classroom modelling is the stricter of the two.
Validity	2 December 2020 – 31 December 2026	Check the end date against your project date. See section 5.
Certificate holder	Company name and registered address	Must match the company actually invoicing you.

That last row catches more problems than it should. A certificate held by a different legal entity — a parent company, a trading arm, a mill the supplier buys from — is not automatically a certificate for the goods on your order. Compare the name on the certificate with the name on the quotation.

4. How to check the certificate is real

A PDF proves nothing on its own. Verification takes about a minute:

Any supplier who cannot complete step 2 has not given you a certificate. The database is public, so this check does not depend on the supplier’s cooperation beyond handing over the ID.

5. The field almost everyone skips

In reviewing how this subject is covered elsewhere, one omission was consistent: almost nobody mentions that certificates expire. Articles explain what Green Label Plus is and that it helps with LEED, then stop.

It matters for a practical reason. Specification, tender, production and installation can span a year or more on a commercial project. A certificate that was valid when the product was specified may not be valid when it ships — and a green building submission rests on the status at the time it is assessed, not at the time someone downloaded the PDF.

So we will state ours plainly rather than bury it: certificate GLP100230 runs to 31 December 2026. If you are reading this after that date, ask us for the renewed certificate and check the ID again — and apply the same test to every other supplier you are comparing.

The general principle: a supplier who volunteers the expiry date without being asked is telling you something about how they handle documentation. One who sends a certificate with the date cropped out is also telling you something.

6. Why the dyeing method affects emissions

Low emissions are a result, not a feature that gets added at the end. One of the larger contributors is how colour gets into the yarn.

In solution dyeing, pigment is added to the polymer before the fibre is extruded, so colour is part of the fibre itself. In conventional piece or yarn dyeing, undyed fibre is made first and colour is applied afterwards in a wet process, with the auxiliaries and finishing that implies.

Solution dyeing is usually discussed for colourfastness — pigment locked into the fibre will not wash or fade out. The emissions side is the less obvious benefit: fewer wet processing stages downstream means fewer residues in the finished tile.

For what it is worth in our own range, and this is drawn from our live product catalogue rather than from a brochure:

Dyeing method	Colourways	Products
Solution dyed	664	81
Solution dyed with space dyeing	100	11
Total	764	92

Every colourway we currently list is solution dyed in whole or in part. That is not a claim about being greener than anyone else — plenty of manufacturers solution dye. It is a statement about what the certificate is describing: a construction whose colour was never applied in a downstream wet process.

Overhead view of carpet tile laid in a gradient from blue through neutral to green, with a timber counter and stools — A gradient laid across a floor is only practical when colour is consistent enough to blend tile to tile. Pigment carried inside the fibre is what makes that possible — the same property that removes a stage of wet processing from the manufacturing route.

7. What Green Label Plus does not tell you

Certification is a floor, not a summary of a product. Being straight about the boundaries:

It says nothing about durability. A tile can be very low emitting and still flatten in a corridor within two years. Resilience, fibre and construction are separate questions with separate evidence.
It is not a whole-catalogue guarantee. The certificate names a product category. If you are buying a construction outside that category, ask whether it is covered — the honest answer is sometimes no.
It does not cover installation. Adhesives are certified separately under the same programme. A low-emitting tile fitted with an uncertified adhesive is not a low-emitting floor.
It is not an environmental footprint. Emissions into indoor air and carbon impact are different measurements. If you need the second, ask for the EPD.
It does not replace regional requirements. Projects in China, for instance, are usually assessed against GB 18587-2001 for carpet emissions, which is a separate certificate again.

Where the certificate genuinely earns its place is in removing a question from the table. Once you have checked the ID, the category and the date, indoor air emissions stop being a matter of trusting the supplier and become a matter of record — which is the only reason a certification programme is worth anything at all.

Frequently asked questions

What does Green Label Plus actually measure?

Chemical emissions from the finished product into indoor air, tested in a chamber to California Department of Public Health Section 01350. The programme screens the 31 compounds listed in that standard plus six specific to carpet, and requires emissions no higher than half the chronic reference exposure level for each — formaldehyde being the exception, which is held to the full level.

Is a low TVOC figure enough on its own?

No. TVOC is a total, and a total can hide an individual compound sitting near its limit. Green Label Plus is useful precisely because it tests named compounds individually rather than only reporting the sum. Treat the TVOC figure as a summary of a test that went deeper, not as the whole result.

What does a category code like CN13 mean on the certificate?

It identifies the product construction that was tested — in our case nylon with PVC backing in modular tile format. This matters more than buyers usually realise: a certificate covers the construction submitted for testing, not automatically every product in a supplier's catalogue. Check that the category matches what you are actually buying.

How do I verify a supplier's certificate is genuine?

Every certified product is issued a label ID by CRI and listed in the certified-products database on carpet-rug.org. Take the ID from the certificate you were sent and look it up. If the supplier will not give you the ID, or the ID does not resolve, that is your answer.

Does Green Label Plus count towards LEED?

It is recognised by USGBC for the Low-Emitting Materials credit under LEED v4.1 and v5. It can also support submissions under other green building frameworks. Confirm the current credit language with your assessor, since credit requirements are revised over time while a certificate is not.

What is UNIJOY's certificate and when does it expire?

Certificate GLP100230, issued by The Carpet and Rug Institute, covering category CN13 — nylon carpet tile with PVC backing — at TVOC of 0.5 mg/m³ or below under both private-office and school-classroom scenarios. It runs to 31 December 2026. The PDF is on our downloads page, and you are welcome to verify the ID against CRI's database rather than take our word for it.

Sources & further reading

Figures attributed to other manufacturers are their own published values, quoted for context. Different laboratories, sample build-ups and substrates are not directly comparable.